Configuration and Control of Cycloconverter for Low Frequency AC Transmission System in 500kv Transmission Line

Abstract

Today, the highest voltage level of the AC power transmission line is 500kV in Myanmar. The highest voltage level encounters the
difficulties of the material and environment issues. If it is a long-distance transmission, its power losses and voltage regulation
are increasing. High voltage 50Hz AC transmission system has many limitations, so a high voltage Low-Frequency AC (LFAC) transmission system has been proposed as a new alternative technology for transmission of power between Meikhtila and
Taungoo transmission system. The low-frequency AC transmission system is the 500kV transmission system. The low-frequency
AC transmission system utilizes the low frequency for transmission of power in this transmission line. This system would like to be
built a low-frequency AC transmission system that used two cycloconverter at the sending end and the receiving end. This paper
focuses on the simulation for three-phase six pulse bridge cycloconverter for low-frequency AC (LFAC) transmission system. This
system uses cycloconverter model and cycloconverter control that included voltage control, current limiter, extinction angle
control and Virtual Synchronous Generator (VSG) which used the Runge-Kutta Method between Meikhtila and Taungoo
transmission system. This converter control model used in LFAC system satisfies in long-distance transmission and increases
voltage level in the transmission line because our country increases in load demands. The MATLAB-SIMULINK model for threephase six pulse bridge cycloconverter has been constructed for a 500 kV LFAC transmission system. LFAC system described that it is nearly 800MW the maximum active power transfer capacity by using the cycloconverter control.